Category Archives: Things of the Moment

Thing of the Moment is where I find something of interest to print, either useful or fun!

Due to work I have not been able to give the time that I would have liked to the site but I am still working on it. I have today’s TotM and a special feature coming soon.

So today’s TotM is a wall monitor arm by makedave. I have three monitors for my computer as I like gaming using ATI’s Eyefinity. At the moment they are a little low on my desk so rather then make a box for them to sit on – I am printing off some wall mounts.

Arm under test

The rig is being tested at the moment. My monitors weigh in at a little over 3kg and the dumbbell comes in a 4.5kg. As the arm toke up the weight the were no issues – the arm not even flexing as it was loaded. Once I am happy that they will take the load – I’ll finish the rig to attach them to my desk.

Thing of the Moment is where I find something of interest to print, either useful or fun!

Building your own 3D printer is fantastic. You learn all there is to know about it and how to fix it should something go wrong. Most people out there can probably build a Prusa Mendel with a little bit of time and patience. There are however two parts of a 3D printer that I feel are the most difficult to produce for people wanting to get into 3D printing. Firstly is the hot-end – which often requires some metal turning on a lathe. Second is the extruder – or more specifically the ‘hobbed’ nut of the extruder. While it is possible to make a hobbed nut with a Dremel like tool – it is time consuming and fiddly. Now there is an alternative.

A user on Thingiverse – profezzorn – has modified a Wade’s extruder to use nothing more then a Dremel #196 bit.

The Dremel #196 bit

Tools position in the extruder

Unlike a hand made hobbed nut this will have precisely spaced teeth and given that it is meant for cutting anything from wood to soft metals – it should have a good bite into the filament. Just be careful not to tighten it too much it might go through!

Thing of the Moment is where I find something of interest to print, either useful or fun!

Think of a 3D printer and you will probably think of it having 3 linear axis’ x (left/right) , y (forward/back) and z (up/down) . When you want to move in one direction you move the axis that way. It’s simple and it works – which is why all the 3D printers I have seen operate in that way. But does it have to be that way? The answer would seem to be – no. Step in Rostock.

Up and Down
Like a conventional printer the Rostock has 3 axis – but that is where the similarities stop. On the Rostock the axis all go up and down. No left or right or forward or back. The axis are placed on the corners of a triangle and the print head is attached by rods connected by linear bearings on each axis. With the rods using universal joints they have a wide range of movement. To make the printer produce a straight line all three axis move at varying rates and varying speeds. To update the saying – a video is worth a thousand words:

At a Price
So why is it that not all printers are made this way? Well reading up it seems that geometry calculations needed to move the head even in a simple line are complicated. However this method does reduce the number of parts the printer is made from – about 200. It should be easier to build as well.

Thing of the Moment is where I find something of interest to print, either useful or fun!

Recently I have been printing things for people. One of the problems has been trying to describe all the colours that I have available to print with. Over a period of time I seem to have a large variety from Faberdashery! While going through Thingiverse I found filament frame – by uBlitz – to hold small samples of the filament I have. The original was designed in Solidworks so was a static model – nothing could be changed aside from editing the STL file (I don’t have Solidworks). Then I noticed a derivative – by MarcoAlic – which is parametric using OpenSCAD. The first print didn’t go so well. Although it was set to make 1.75mm diameter holes they just weren’t big enough to hold the filament. The second problem was that the outside wall was just 1mm and Slic3r didn’t like that. In the end I adjusted the OpenSCAD script to reduce the size of the cylinders a little – 1mm overall and entered a filament diameter of 1.9mm. This sorted the problem.

On the whole I think it turned out okay. Now I can simple show people what I have rather then trying to describe them.

Thing of the Moment is where I find something of interest to print, either useful or fun!

So today I write about an item I have created to help me store my electronic components. I had been searching for a way to safely hold all my small components without having to use the more standard larger storage system. I had a look on Thingiverse any while there are a few options none suited my needs. The storage draw system I came up with is based around the larger type – except that the draws are designed to be only a bit larger then a resistor is long with its legs attached. Actually a ATMEGA644 can fit in with room to spare.

The design is partly parametric – the rack is parametric in as much as the number of rows and columns can be decided – along with the any rows that will have half height draws. To stop the draws falling out the back of the racks there is a bar to prevent that. The draws are static, designed in SketchUp. On my Huxley I can print a 4×4 large grid as a maximum. In order to reduce the amount of filament used the walls of the rack and draws are only 1mm thick – so there is no infill – but they more then strong enough.

Overall I am happy with the way that this has turned out. The design allows for all of the items that I own to be stored easily and only taking up the minimum of shelf space.

Yesterday master 3D Thingsmith RichRap posted a tweet that he had got Printrun working on his Raspberry Pi. For those who don’t know the Raspberry Pi is a single board computer based around an ARM processor and Linux and is very cheap – about $35.

Mainly it was designed to try and get programming of computers back into UK schools – something that has dropped off in favour of just using software. Why is this event remotely interesting? For me it is being able to fully control my Huxley without having to have my main computer running, consuming a maximum on 7 watts rather than a minimum of 120 watts!

ARM Slicing?
The more interesting thing is if RichRap has the slicing software going to. To be honest it would be painfully slow, unless somehow it used the GPU to help with the computing – and that is unlikely!

Make one yourself
RichRap has said that he will be putting a blog post up on how he done it – allowing anyone with a Pi to be able to follow. Once they are up I will attempt it myself and report back!

Thing of the Moment is where I find something of interest to print, either useful or fun!

On Saturday I finally got my hands on a RaspberryPi. Having played with it for a bit I can see it will have an uphill climb. However one thing it does need is a case. Popping in ‘raspberry’ as a search on Thingiverse brought up a number of options. Looking through I settled on the case by HansH.

Case of two halves
Part of the reason I went for this is the case is designed in two parts and you have a selection. Also it is made in openSCAD so it should possible to modify for your own tastes. I just picked a base and a top with a raspberry in.

Two parts, two colours
According to Slic3r I would have to use about 6m of filament. I have been trying to use up the remnants I have had laying around so printed the base in black and lid in red. The parts clip together nicely without fittings.

And finally
It has gone together nicely, I have had to adjust some of the ports to get access fully and to make it close. That said it is a great looking case and works really well.